Citation de code source en JavaScriptn° 91

window.setTimeout(function() {
        $('#preloader_navigation_instructions_2')
        .animate({
            opacity: 1
        }, 400);
        $('#preloader_navigation_instructions_1')
        .animate({
            opacity: 0
        }, 400, function() {
            window.setTimeout(function() {
                $('#preloader_navigation_instructions_3')
                .animate({
                    opacity: 1
                }, 400);
                $('#preloader_navigation_instructions_2')
                .animate({
                    opacity: 0
                }, 400, function() {
                    window.setTimeout(function() {
                        $('#preloader_navigation_instructions_4')
                        .animate({
                            opacity: 1
                        }, 400);
                        $('#preloader_navigation_instructions_3')
                        .animate({
                            opacity: 0
                        }, 400, function() {
                            window.setTimeout(function() {
                                $('#preloader_navigation_instructions_5')
                                .animate({
                                    opacity: 1
                                }, 400);
                                $('#preloader_navigation_instructions_4')
                                .animate({
                                    opacity: 0
                                }, 400, function() {
                                    window.setTimeout(function() {
                                        $('#preloader_navigation_instructions_6')
                                        .animate({
                                            opacity: 1
                                        }, 400);
                                        $('#preloader_navigation_instructions_5')
                                        .animate({
                                            opacity: 0
                                        }, 400, function() {
                                            window.setTimeout(function() {
                                                $('#preloader_navigation_instructions_7')
                                                .animate({
                                                    opacity: 1
                                                }, 400);
                                                $('#preloader_navigation_instructions_6')
                                                .animate({
                                                    opacity: 0
                                                }, 400, function() {
                                                    window.setTimeout(function() {
                                                        $('#preloader_navigation_instructions_8')
                                                        .animate({
                                                            opacity: 1
                                                        }, 400);
                                                        $('#preloader_navigation_instructions_7')
                                                        .animate({
                                                            opacity: 0
                                                        }, 400, function() {
                                                            window.setTimeout(function() {
                                                                $('#preloader_navigation_instructions_9')
                                                                .animate({
                                                                    opacity: 1
                                                                }, 400);
                                                                $('#preloader_navigation_instructions_8')
                                                                .animate({
                                                                    opacity: 0
                                                                }, 400, function() {
                                                                    window.setTimeout(function() {
                                                                        $('#preloader_navigation_instructions_9')
                                                                        .animate({
                                                                            opacity: 1
                                                                        }, 400, function() {
                                                                            window.setTimeout(function() {
                                                                                $('#preloader_navigation_instructions_9')
                                                                                .animate({
                                                                                    opacity: 0
                                                                                }, 400);
                                                                                preloaderInstructionsEnded();
                                                                            }, 600);
                                                                        });
                                                                    }, 600);
                                                                })
                                                            }, 600);
                                                        })
                                                    }, 600);
                                                })
                                            }, 600);
                                        })
                                    }, 600);
                                })
                            }, 600);
                        })
                    }, 600);
                })
            }, 600);
        })
}, 1000);